In the description of the background of the present invention that follows reference is made to certain structures and methods, however, such references should not necessarily be construed as an admission that these structures and methods qualify as prior art under the applicable statutory provisions. Applicants reserve the right to demonstrate that any of the referenced subject matter does not constitute prior art with regard to the present invention.
Hard material layers for reducing wear, for reducing friction or for similar purposes are known in different compositions and production methods. Titanium-boron nitride layers (TiBN layers) in particular are known. In this connection, DE 43 43 354 A1 discloses the production of TiBN layers by means of the PVD process. The TiBN layer is created by PVD vaporization of titanium boride at a coating temperature of approximately 200° C. The deposition of titanium boride takes place from a coating plasma.
It is difficult to integrate the PVD production of a TiBN layer into a process which produces other layers by means of the CVD process.
Layer structures containing TiBN layers are known from EP 0 732 423 B1. The TiBN layers are intended as intermediate layers between other layers for improving adhesion. The layers are created at a deposit temperature of 1000° C. by means of a CVD process.
The creation of a TiBN layer which consists of the layered components TiNX and TiB2 is known from a publication of Bartsch, Leonhardt, Wolf entitled “Composition Oscillations in Hard Material Layers Deposited from the Vapour Phase” in Journal de Physique IV, Colloque C2, Suppl. au Journal de Physique II, Vol. 1, September 1991. For generating these oscillating layers, the coating was performed in a cold wall reactor at a temperature of 1300 K (approximately 1000° C.) by means of the CVD process.